Cannot connect zimbra email accounts outside local network

[awb23]

Good Day everyone!

Why is it that, when we try to setup email account outside our network using outlook,
we cannot connect?

also, tried using the same PC which is already connected to email account, when changing the PC network (using dif ISP)
it cannot connect to email account.

we want some of our employees to access their email account from home.

Please help.

Zimbra version:
Release 8.8.8_GA_2009.RHEL7_64_20180322150747 RHEL7_64 FOSS edition

[awb23]

Good Day,

How can we see the imap/pop3 details from zimbra server which will we put to outlook?

We need to setup some of our users emails outside our office or to their homes.
Please help.

[awb23]

When I try to set it up on my android using POP3, i get this message
"Couldn't open connection to server."

Please help!

[7224jobe]

Hi, are there any firewalls between internet and your Zimbra server? Are there any rules regarding these ports?
25 smtp mta incoming mail to postfix
80 http mailbox / proxy web mail client (disabled by default in 8.0)
110 pop3 mailbox / proxy POP3
143 imap mailbox / proxy IMAP
443 https mailbox / proxy - web mail client HTTP over TLS
465 smtps mta Incoming mail to postfix over TLS (Legacy Outlook only? If possible, use 587 instead)
587 smtp mta Mail submission over TLS
993 imaps mailbox / proxy IMAP over TLS
995 pop3s mailbox / proxy POP3 over TLS

[awb23]

Hello Sir Jobe.
Thank you for your response.

Yes there is a firewall.
I temporarily opened these ports for testing. but no luck

open ports.png (10.9 KiB) Viewed 2534 times

Is there any other ports i need to open?

[phoenix]

You haven't actually mentioned how your Outlook users are connecting to the ZCS server, which port are they actually using?